The Hybrid Organic‐Inorganic 2‐D Material (CsNa 2 [{Sn(CH 3 ) 2 } 3 (H 2 O) 4 (β‐XW 9 O 33 )]·7H 2 O) ∞ (X = As III , Sb III ) and Its Solution Properties

We report on the hybrid organic‐inorganic 2‐D materials (CsNa 2 [{Sn(CH 3 ) 2 } 3 (H 2 O) 4 (β‐AsW 9 O 33 )]·7H 2 O) ∞ ( 1a ) and the isomorphous (CsNa 2 [{Sn(CH 3 ) 2 } 3 (H 2 O) 4 (β‐SbW 9 O 33 )]·7H 2 O) ∞ ( 2a ) which crystallize in the orthorhombic system, space group Pna 2 1 , with identical unit cell parameters a = 26.118(2) Å, b = 16.064(1) Å, c = 13.776(1) Å, and Z = 1. Compounds 1a and 2a have been synthesized in good yield by crystallization from a reaction mixture of dimethyltin dichloride and Na 9 [α‐XW 9 O 33 ] (X = As III , Sb III ) in aqueous, acidic medium. We have shown by multinuclear NMR spectroscopy ( 183 W, 119 Sn, 13 C, 1 H) that 1a and 2a decompose in solution leading to the monomeric species [{Sn(CH 3 ) 2 (H 2 O) 2 } 3 (β‐XW 9 O 33 )] 3− [X = As III ( 1 ), Sb III ( 2 )]. Polyanions 1 and 2 consist of a (β‐XW 9 O 33 ) fragment stabilized by three dimethyltin units. The dimethyltin groups are grafted onto the polyanion by two Sn−O(W) bonds on the side of the heteroatom lone pair. Compounds 1 and 2 are rare examples of discrete polyoxoanions which polymerize upon crystallization leading to a 2‐D solid‐state structure with inorganic and organic surface regions. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)